Light Weight Directory Access Protocol (LDAP) has become very popular due to its efficient and fast data access. A large number of applications/services are currently being developed which use an LDAP directory as their centralized data repository.
In the LDAP directory, data is stored as entries including key/value pairs. A key/value pair may consist of an attribute name and an attribute value. For example, an entry for an attribute known as a file type attribute may include a specific file type as the attribute name and the content of the file as the attribute value.
Some file types may include a set of metadata stored inside the file. For example, jpegphoto Exchangeable Image File Format (EXIF) used for compressed digital camera images includes multiple metadata fields for describing properties of an image stored in the file. These properties may specify the date when the picture was taken, the camera model used for taking the picture, the vertical and horizontal size of the picture, etc. This additional information might be useful for performing searches of the LDAP directory. However, no efficient mechanism currently exists for searching LDAP directory entries based on specific metadata properties stored inside the files.